1. Field of the Invention
This invention relates to a surge voltage arrester with a gastight housing in which electrodes are arranged opposite one another, forming a gap, and are inserted into the ends of a tube-shaped insulating body having an inner surface which carries at least one strip of electrically conductive material as an ignition strip, the strip extending over a part of the tube length commencing from one electrode toward the other electrode.
2. Description of the Prior Art
It is known in the art that in order to reduce the ignition voltage in gas discharge tubes one may apply ignition strips of electrically conductive material to the tube-shaped insulating body of a gas discharge tube. For example, reference may be taken to German Pat. No. 1,070,733. In surge voltage arresters of this kind, the filling of the arrester with radioactive preparates is avoided, or at least substantially reduced. The ignition strips are preferably applied to the inside of the insulating body and in each case are connected to an electrode.
In the case of rapidly rising surge voltages (impulse sparkover voltage) surge voltage arresters are to ignite as quickly as possible. In the German published application No. 2,032,899 the application of ignition strips to a ceramic body in order to achieve a rapid response of the surge voltage arrester is disclosed. The ignition strip can be either electrically conductively connected to the electrodes or not so connected to the electrodes. The embodiment in which the ignition strip is electrically connected to the electrodes is preferred. A metallic solder is employed as a connection element. In the known surge voltage arrester, the ignition strip is designed in such a manner that it terminates at a distance in front of the counter electrode at the level of the gap formed between the two electrodes, so that it is not possisble for an arc flashover to take place between the ignition strip and the counter electrode. In a particular embodiment of that invention, the ignition strip is electrically connected to one of the electrodes and extends in the direction toward the other electrode, wherein the ignition strip terminates at a distance before the other electrode, which distance is greater than the gap between the two electrodes. In this known series voltage arrester it is very difficult to apply to the insulating body ignition strips which end very precisely at a specific point which has a greater distance from the counter electrode than the distance between the two electrodes.